Fascinating Illusion Uses Mirror to Turn Rectangles into Circles

What in the world is going on here? we still don't really know but the illusion titled ‘Rectangles and Circles’ from Kokichi Sugihara turns squares into circles and circles into squares right in front of our eyes.

Different shapes are placed in front of a mirror and what's reflected back looks nothing like what you're looking at, almost as if the mirror isn't a mirror at all and instead a window to parallel universe or something. Who knows? check out the cool illusion in the video below.